A fanconi anemia complementation group protein that undergoes mono-ubiquitination by FANCL PROTEIN in response to dna damage. Also, in response to IONIZING radiation it can undergo phosphorylation by ataxia telangiectasia mutated protein. Modified FANCD2 interacts with brca2 protein in a stable complex with chromatin, and it is involved in dna repair by homologous recombination.